Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine Year 1 - Semester 2 - Part 2 > Overview of Cancer Chemotherapy > Flashcards

Overview of Cancer Chemotherapy Flashcards

1
Q

What is cancer ?

A

Neoplasia - new growth

Uncontrolled proliferation of abnormal forms of the body’s own cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Characteristics of cancer cells

A
  1. Uncontrolled proliferation
  2. Invasiveness
  3. Metastases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

State the 2 main causes of cancer

A

Mutations in DNA resulting in production of altered cells which have changes in proliferating mechanisms.

OR

Changes in the DNA caused by covalent modification.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Changes in the DNA caused by covalent modification

A

Spontaneous or genetic predisposition

Ionising Radiation or UV radiation

Chemical Carcinogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Key feature of cancer

A

Cancer is a multi-step process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

State the 3 main approaches to dealing withe established cancers

A

Surgical excision
Radiotherapy
Chemotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Immune response

A

Good anti-microbial
Poor anti-cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Body defences response

A

Good anti-microbial
Poor anti-cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mechanism of action of alkylating agents

A

Alkylation of the 7 nitrogen - destabilises the IMIDAZOLE ring.

Opening of the IMIDAZOLE ring

Depurination-excision of guanine residues and repair of DNA - opportunity for mutation

This resulting damage to DNA by alkylating agents triggers cell death by apoptosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

State the 4 types of traditional agents (cancer chemotherapies)

A

Alkylating agents
Antimetabolites
Cytotoxic antibiotics
Plant derivatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe Alkylating agents

A

Most commonly employed anti-cancer drugs.

Bind DNA in cancer cells, causing cell death.

Intra-strand cross-linking of DNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are alkylating agents capable of doing ?

A

Forming covalent bonds with suitable nucleophilic substances in the cell under physiological conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe guanine residues in DNA

A

Normally guanine residues in DNA exist predominantly in the keto tautomer.

This allows them to form base pairs with cytosine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe alkylation of guanine

A

When the 7position nitrogen of guanine is alkylated it becomes more acidic and the keto turns into enos.

This modified guanine can mispair with thymine residues in DNA synthesis.

This creates a mutation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Example of Nitrogen mustards

A

Cyclophosphamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

State the 6 major classes of alkylating agents

A

Nitrogen mustards
Ethylenimines
Alkylsulphonates
Hydrazines and Traizines
Nitrosoureas
Platinum based compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Example of Ethylenimines

A

Thiotepa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Example of Alkylsulphonates

A

Busulphan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Example of Hydrazines and Traizines

A

Temozolomide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Example of Nitrosoureas

A

Lomustine, Carmustine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Example of Platinum based compounds

A

Cisplatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the action of nitrogen mustards - e.g. cyclophosphamide

A

Cyclophosphamide activated in the liver by P450 mixed function oxidases.

Involved in cross-linking of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe the action of alkylsuphonates - e.g. busulphan

A

Busulphan has a selective effect on the bone marrow.

Used in chronic granulocytic leukaemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Busulphan

A

Selective effect on the bone marrow, depressing the formation of granulocytes and platelets in low dosage and red cells in high dosage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the action of platinum based compounds - e.g. cisplatin

A

Action is analogous to that of the alkylating agents.

Binds DNA - causes intrastrand cross-links

Used for ovarian cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the action of nitrosoureas - e.g. lomustine, carmustine

A

These drugs are LIPID soluble and can therefore cross the blood-brain barrier.

May be used against tumours of the brain and meninges.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

State the major groups of anti-metabolites

A

Antifolates
Antipyramidines
Antipurines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Example of an antifolate

A

Methotrexate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Example of an antipyramidine

A

5-FU
Gemcitabine

27
Q

Example of an antipurine

A

Mercatopurine
Thioguanine

28
Q

Describe antifolate - methotrexate

A

Folate analogue

  • usually given orally
  • low lipid solubility, so doesn’t cross blood brain barrier easily
  • polyglutamated which means it can be retained within cells for weeks
29
Q

Key feature of antifolates - methotrexate

A

Polyglutamated which means it can be retained within cells for weeks

30
Q

Describe antipyramidines - fluorouracil 5-FU

A

Fluorouracil interferes with thymidylate synthesis (DTMP)

It is converted into FDUMP - fraudulent nucleotide

This inhibits DNA polymerase.

31
Q

Action of fludarabine

A

Antipurine

  • Fludarabine in its triphosphate form inhibits DNA polymerase
32
Q

Function of cytotoxic antibiotics

A

Anti-tumour antibiotics produce their effects mainly by direct action on DNA.

33
Q

Give some classes of cytotoxic antibiotics

A

Anthracyclines
Dactinomycin
Bleomycin
Mitomycin

34
Q

Example of anthracyclines

A

Doxorubicin

35
Q

Mechanism of action of doxorubicin

A

It binds to DNA and inhibits both DNA and RNA synthesis.

Main cytotoxic effect appears to be mediated through an effect on topoisomerase 2 - the activity of which is markedly increased in proliferating cells.

36
Q

Action of doxorubicin on DNA-topoisomerase II

A

Doxorubicin intercalates into DNA and blocks the DNA-topoisomerase II complex.

37
Q

Dactinomycin action

A

Interfering with the movement of RNA polymerase along the gene - preventing transcription.

38
Q

Bleomycins action

A

Degrade preformed DNA, causing chain fragmentation and release of free bases.

38
Q

Mitomycin action

A

After enzymatic activation in cells, functions as a bifunctional alkylating agent.

Cross-links DNA and may degrade DNA through generation of free radicals.

39
Q

Plant derivatives functions

A

Spindle poisons - affect microtubule function and prevent mitotic spindle formation

Vinca Alkaloids & Taxanes: inhibit MT function

Captothecins & Etoposide: inhibit RNA synthesis and topoisomerase 2

40
Q

Common plant derivatives

A

Vinca alkaloids

Taxanes

Camptothecins

Etoposide

41
Q

Function of vinca alkaloids

A

Binds tubules and prevents polymerisation into microtubules

42
Q

Function of taxanes

A

Stabilises (freezes) microtubules

43
Q

Function of camptothecins

A

Binds to and inhibits topoisomerase I

44
Q

Function of etoposide

A

Inhibits mitochondrial function, nucleoside transport and topoisomerase II.

45
Q

Example of vinca alkaloids

A

Vincristine
Vinblastine

46
Q

Example of taxanes

A

Paclitaxcel
Docetaxel

47
Q

Example of Camptothecins

A

Irinotecan

48
Q

State some other anti-cancer drugs

A

Hormones (hormone inhibitors)

Monoclonal antibodies
Protein kinase inhibitors

Miscellaneous agents

49
Q

Drawbacks of chemotherapy of cancer

A

Target cell proliferation NOT the more lethal properties of invasiveness and metastases.

Non-specific cell killers rather than being aimed at the particular changes which make a cell malignant.

The development of resistance to anti-cancer drugs.

Leaves some remaining cells

50
Q

Describe the side-effects caused by chemotherapy

A

Side effects relate to body systems:

Healthy cells which have a high rate of growth and multiplication include cells of bone marrow, hair, GI mucosa and skin.

51
Q

When do side effects of cancer chemotherapy occur ?

A

7-14 days post cancer treatment.

This can be cumulative over many cycles.

52
Q

KEY drawback of chemotherapy

A

Patient compliance due to side-effects

Not competing the therapy regimen.

53
Q

Tumour Lysis Syndrome

A

Acute side-effect and a metabolic emergency.

Occurs due to rapid cell lysis and large amounts of cell metabolites in blood.

Characterised by hyper:
- Uricaemia
- Phosphataemia
- Kalaemia

Hypocalcaemia

54
Q

If tumour lysis syndrome is left untreated what can it cause ?

A

Acute renal failure
Cardiac arrest
Death

55
Q

State some specific side effects to systems of chemo

A

Bone Marrow
Gastro-intestinal
Mucositis

56
Q

Fatigue

A

Often multi-factorial, treat cause if known, involves physio/occupational therapists in care.

57
Q

Body image side effects

A

Hair loss
Weight gain/loss
Appearance of intervention wounds

58
Q

Altered renal function

A

Care with drug choices, dose and frequency

58
Q

Peripheral neuropathy

A

Counsel patient about the need for care if injured, consider analgesia for nerve pain.

59
Q

Delayed effects of chemo

A

Infertility
Secondary Malignancy

60
Q

Key action of methotrexate

A

Inhibits:

  • purine synthesis
  • DTMP synthesis
61
Q

Key action of 5-fluorouracil

A

Inhibits DTMP synthesis

62
Q

Key action of alkylating agents

A

Cross-links DNA

63
Q

Key action of doxorubicin, etoposide, amasacrine, campothecins

A

Inhibit:

  • topoisomerase II
  • RNA synthesis
64
Q

Key action of dacintomycin

A

Intercalates in DNA

Inhibits:

  • Topoisomerase II
  • RNA synthesis
65
Q

Key action of Vinca Alkaloids, Taxanes

A

Inhibits function of microtubules

66
Q

Key action of cytarabine

A

Inhibits:

  • DNA polymerase
  • RNA function

Medicine Year 1 - Semester 2 - Part 2 (53 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions